Surgical probe

ABSTRACT

An exemplary surgical probe and methods of making the same are disclosed. An exemplary surgical probe may include a tubular body and a scissor assembly received at least partially within the body. The scissor assembly may include a first blade fixed to the tubular body that includes a body portion and an end portion. The scissor assembly may further include a second blade that is configured to move longitudinally within the tubular body. The body portions of the first and second blades may each define respective cross sections normal to a longitudinal axis of the tubular body. The cross sections may each define centrally disposed edges adjacent one another, and the cross sections may each be asymmetrical about a line substantially parallel to the centrally disposed edges.

This application is a divisional of U.S. patent application Ser. No.13/900,160 filed on May 22, 2013, which is a continuation of U.S. patentapplication Ser. No. 13/010,966 filed on Jan. 21, 2011.

BACKGROUND

Many microsurgical procedures require precision cutting and/or removalof various body tissues. For example, vitreoretinal surgery oftenrequires the cutting, removal, dissection, delamination, coagulation, orother manipulation of delicate tissues such as the vitreous humor,traction bands, membranes, or the retina. The vitreous humor, orvitreous, is composed of numerous microscopic fibers that are oftenattached to the retina. Therefore, cutting, removal, or othermanipulation of the vitreous must be done with great care to avoidtraction on the retina, the separation of the retina from the choroid, aretinal tear, or, in the worst case, cutting and removal of the retinaitself.

Microsurgical instruments, such as vitrectomy probes, fiber opticilluminators, infusion cannulas, aspiration probes, scissors, forceps,and lasers are typically utilized during vitreoretinal surgery. Thesedevices are generally inserted through one or more surgical incisions inthe sclera near the pars plana, which are called sclerotomies. Oneexemplary surgical probe includes a cutting blade disposed within atubular probe needle. The cutting blade moves reciprocally within theprobe needle relative to a second blade that is fixed within the tubularneedle. The moving blade cuts material, e.g., vitreous humor, in ascissor-like motion adjacent the fixed blade.

To reduce potential damage to surgical sites and reduce recovery time,the size of the surgical incisions must be kept to a minimum.Accordingly, surgical probes are being designed in progressively smallersizes to facilitate correspondingly smaller surgical incisions. As probesize decreases, cutting blades within the probes are decreased in sizeas well, thereby reducing blade strength and increasing the risk offatigue or failure. Further, known mechanical forming methodologies suchas grinding or machining are impractical at the small sizes typical ofthe blades, which typically have a maximum cross-sectional width of lessthan one (1) millimeter. Additionally, known forming processes aregenerally limited to blades having cross sections defining rectangularshapes, which prevents widening the blades to increase strength.Accordingly, current manufacturing methodologies and blade strengthinhibit the degree to which probe needles may desirably be furtherreduced in size.

BRIEF DESCRIPTION OF THE DRAWINGS

While the claims are not limited to the illustrated examples, anappreciation of various aspects is best gained through a discussion ofvarious examples thereof. Referring now to the drawings, illustrativeexamples are shown in detail. Although the drawings represent thevarious examples, the drawings are not necessarily to scale and certainfeatures may be exaggerated to better illustrate and explain aninnovative aspect of an example. Further, the examples described hereinare not intended to be exhaustive or otherwise limiting or restrictingto the precise form and configuration shown in the drawings anddisclosed in the following detailed description. Exemplary illustrationsof the present invention are described in detail by referring to thedrawings as follows.

FIG. 1A illustrates a perspective view of an exemplary surgical probe;

FIG. 1B illustrates a perspective view of an tubular body and scissorassembly of the surgical probe of FIG. 1A;

FIG. 2A illustrates an enlarged perspective view of the exemplarysurgical probe of FIGS. 1A and 1B;

FIG. 2B illustrates an enlarged perspective view of the exemplarysurgical probe of FIGS. 1A and 1B, taken from an opposite side of theprobe compared with FIG. 2A;

FIG. 3A illustrates a cross sectional view of an exemplary surgicalprobe;

FIG. 3B illustrates a cross sectional view of another exemplary surgicalprobe;

FIG. 4 illustrates a perspective view of an exemplary blade sheet usedto produce blades for a surgical probe;

FIG. 5 illustrates a cross sectional view of the exemplary blade sheetof FIG. 4; and

FIG. 6 illustrates a process flow diagram of an exemplary method offorming a surgical probe.

DETAILED DESCRIPTION

Various exemplary illustrations are described herein of a surgical probeand methods of making the same. An exemplary surgical probe may includea tubular body defining a cutting aperture at a first end of the body.The surgical probe may further include a scissor assembly received atleast partially within the body and extending along a longitudinal axisof the body. The scissor assembly may further include a first bladefixed to the tubular body that includes a body portion and an endportion. The scissor assembly may further include a second blade that isconfigured to move longitudinally within the tubular body. The secondblade may also include a body portion and a cutting edge at an end ofthe body portion. The cutting edge may be configured to cut material,e.g., against the end portion of the first blade. The body portions ofthe first and second blades may each define respective cross sectionsnormal to a longitudinal axis of the tubular body. The cross sectionsmay each define centrally disposed edges adjacent one another, and thecross sections may each be asymmetrical about a line substantiallyparallel to the centrally disposed edges. As will be described furtherbelow, the asymmetrical cross-sections may allow an enlarged sectionmodulus of the blade body portions, thereby increasing overall strengthof the blades.

Exemplary methods of forming a surgical probe may include forming firstand second blades that include elongated body portions. The first blademay include an end portion, adjacent which a cutting edge of the secondblade may initiate a scissor cutting motion. The exemplary methods mayfurther include establishing the body portions of the first and secondblades as defining asymmetrical cross sections normal to the elongatedbody portions of the blades, relative to a line substantially parallelto centrally disposed edges of the cross sections. The method mayfurther include inserting the first and second blades into a tubularbody having a cutting aperture at a first end of the tubular of thebody, and fixing the first blade to the tubular body. The second blademay be configured to translate longitudinally within the tubular body.

Turning now to FIGS. 1A and 1B, an exemplary probe 100 is illustrated. Asurgical probe 100 may include any ophthalmic surgery probe. Forexample, probe 100 may be a vertical scissor probe, as shown throughoutthe figures and described below. The surgical probe 100 may include ahandle 101 that allows manipulation, e.g., by a surgeon, of a tubularbody 102 secured to the handle 101. The tubular body 102 may beconfigured to be inserted into a surgical incision, e.g., during variousposterior and anterior ophthalmic surgical procedures such asProliferative Vitreoretinopathy (PVR) and pediatric Retinopathy ofPrematurity (ROP), merely as examples. Additionally, as best seen inFIG. 1B, the tubular body 102 may be selectively secured to the handle101 via a connector 103 that facilitates removal and/or replacement ofthe tubular body 102. The tubular body 102 may define a longitudinallyextending axis A-A.

Turning now to FIGS. 2A and 2B, the probe 100 may include a scissorassembly 104 that is received at least partially within the tubular body102 and extends along the longitudinally axis A-A. The scissor assembly104 may include first and second blades 106, 108. The first blade 106may be fixed relative to the tubular body 102, e.g., by welding. Thefirst blade may include a body portion 110 and an end portion 112. Thesecond blade 108 may be configured to move longitudinally within thetubular body 102 relative to the first blade 106 along a cutting path P.The second blade may include a body portion 114 and a cutting edge 116at an end of the body portion 114. The cutting edge 116 may be generallyconfigured to cut material adjacent or against the end portion 112 ofthe first blade 106. More specifically, the cutting edge 116 maygenerally cut material in a scissor-like motion, in cooperation with theend portion 112 of the first blade 106.

As best seen in FIGS. 2A and 2B, the first blade 106 may include arelatively thin neck portion 122 between the end portion 112 and bodyportion 110. The end portion 112 may thereby define a generally “hooked”shape extending laterally, e.g., relative to the axis A-A. The thin neckportion 122 generally facilitates movement of the second blade 108relative to the first blade 106, while allowing a cutting surface S thatallows full engagement of the cutting edge 116. More specifically, theneck portion 122 defines a lateral width W₁ that is smaller than alateral width W₂ of the cutting edge 116. Any wear, e.g., as caused byfriction between the cutting edge 116 and the first blade 106, may bethereby reduced while allowing a relatively larger width of the cuttingedge 116 to be applied to the material (not shown) to be cut.

Turning now to FIG. 3A, which is a cross sectional view of the tubularbody 102 and scissor assembly 104, the scissor assembly 104 isillustrated in further detail. More specifically, FIG. 3A illustrates across sectional view of the body portions 110, 114 of the first blade106 and second blade 108, respectively. As shown in FIG. 3A, the crosssections of the body portions 110, 114 as viewed normal to thelongitudinally axis A-A of the tubular body 102 each define centrallydisposed edges 118 and 120 that are generally adjacent one another.Further, each of the cross sections X and Z of the first and secondblades 106 and 108 are generally asymmetrical with respect to a line B-Bthat is substantially parallel to the centrally disposed edges 118, 120.As will be described further below, the asymmetrical cross sections Xand Z may facilitate an enlarged section modulus compared with bladeshaving a quadrangular-shaped section.

The cross sections X and Z may be substantially defined by the centrallydisposed edges 118, 120, distal edges 128, 130 and lateral edges 132extending therebetween. More specifically, cross section X of the secondblade 108 is generally defined by the edges 118, 132 c, 132 d, and 130,while cross section Z of first blade 106 is defined by edges 120, 132 a,132 b, and 128. The centrally disposed edges 118 and 120 may each extendacross substantially the entire inner diameter of the tubular body 102,and may each be the same general size and cross sectional shape.Alternatively, the blades 106, 108 may be different sizes, e.g., wherefirst blade 106 is enlarged for a more secure positioning within thetubular body 102.

The distal edges 132 of each cross section X and Z are relativelysmaller in extent across the opening defined by the tubular body 102compared with the centrally disposed edges 118, 120. Accordingly, thecross sections X and Z may define a generally trapezoidal shape. As willbe explained further below, the generally trapezoidal shape and/orasymmetrical shape defined by the cross sections X and Z of the bodyportions 110 and 114 of the first and second blades 106 and 106 may begenerally formed in an etching process.

Turning now to FIG. 3B, a cross-sectional view of another exemplaryprobe 100′ is illustrated. As with probe 100 described above, the probe'100 included first and second blades 106, 108 received within tubularbody 102. However, first blade 106 defines a generally symmetricaland/or rectangular cross-section, while the second blade 108 defines agenerally asymmetrical and/or trapezoidal cross-section. Alternatively,the first and second blades 106, 108 may each define an asymmetricaland/or trapezoidal cross-section, e.g., as described above in regard toprobe 100. While one of the first and second blades 106, 108 is fixedwith respect to the tubular body 102, the other may be movable to allowaxial translation with respect to the tubular body 102.

The generally asymmetrical/trapezoidal cross-section of blade 108 maygenerally have an increased section modulus, and thereby provide greaterstrength, compared with the generally symmetrical/rectangular blade 106.Although only one of the blades 106, 108 shown in FIG. 3B has anasymmetrical/trapezoidal cross-section, the exemplary illustration inFIG. 3B is also generally illustrative of the improved strength of anasymmetrical/trapezoidal cross-section compared with asymmetrical/rectangular cross section.

In one exemplary illustration, the tubular body 102 shown in FIG. 3B isprovided in a 23-gauge size having an inner diameter G of 0.45millimeters. The asymmetrical or trapezoidal shape may facilitate anenlarged section and/or an increased section modulus of the blade 108,thereby increasing strength of the asymmetrical/trapezoidal blade 108compared with symmetrical/rectangular blade 106. The blades 106, 108 arespaced apart by a small gap D of 0.01 millimeters. One known blade 106has a rectangular cross section defining a maximum width C of 0.38millimeters and a maximum thickness F of 0.1 millimeters, resulting in across sectional area of 0.038 millimeters² and a section modulus, W_(y),of 0.000633 millimeters³. By contrast, the asymmetrical shape of blade108 allows for an increased length A of the centrally disposed edge 120,which extends 0.44 millimeters, due to the sloped configuration of thelateral edges 132 that create the trapezoidal and/or asymmetrical shape.Further, the thickness E of the blade 108 is increased to 0.15millimeters, which is also facilitated by the sloped lateral edges 132.Additionally, the distal edge defines a width B of 0.3 millimeters.Accordingly, the cross-sectional area of the generally trapezoidal blade108 is increased to 0.056 millimeters². Further, the section modulus,W_(y), is also increased to 0.00129 millimeters³. Accordingly, thetrapezoidal and/or asymmetrical shape of the blade 108 results in anincreased strength of the blade 108 compared with blades having atraditional rectangular-shaped section, e.g., blade 106.

In another exemplary illustration, a 29-gauge size tubular body has aninner diameter of 0.2 millimeters. The blades 106, 108 are spaced apartby a small gap D of 0.004 millimeters. This exemplary illustration ofthe blade 106 has a rectangular cross section defining a maximum width Cof 0.16 millimeters and a maximum thickness F of 0.04 millimeters,resulting in a cross sectional area of 0.0064 millimeters² and a sectionmodulus, W_(y), of 0.00004267 millimeters³. By contrast, an asymmetricalshape such as that shown for blade 108 allows for an increased length Aof the centrally disposed edge 120, which extends 0.19 millimeters, dueto the sloped configuration of the lateral edges 132 that create thetrapezoidal and/or asymmetrical shape. Further, the thickness E of theblade 108 is increased to 0.07 millimeters, which is also facilitated bythe sloped lateral edges 132. Additionally, the distal edge defines awidth B of 0.13 millimeters. Accordingly, the cross-sectional area ofthe blade 108 is increased to 0.0112 millimeters². Further, the sectionmodulus, W_(y), is also increased to 0.000122 millimeters³. Accordingly,the trapezoidal and/or asymmetrical shape of the blade 108 results in anincreased strength of the blade 108 compared with blades having atraditional rectangular-shaped section, e.g., blade 106.

The above dimensions are provided merely as an exemplary illustration ofthe potential for increased strength of the blades 106, 108 that mayresult from the asymmetrical and/or trapezoidal cross-sectional shape.Accordingly, any other dimensions may be employed for blades 106, 108that are convenient.

Turning now to FIG. 4, an exemplary blade sheet assembly 400 used toform a plurality of blades 106 and/or 108 is illustrated. Blade sheet400 generally includes a sheet blank 402 from which a series of blades106 and/or 108 may be formed, in any manner that is convenient.

In one exemplary illustration, blades 106, 108 are formed in an etchingprocess applied to the blade sheet assembly 400. An etching process maybe advantageous as compared with other mechanical forming processeswhere the blades 106, 108 are very small, such that machining orgrinding is impractical. Accordingly, blade sheet assembly 400 mayinclude an inert substance or generally etch resistant substance 404applied to the sheet blank 402. For example, as shown in FIG. 4, aseries of etch resistant strips 404 a, 404 b may be applied to opposingsides of the sheet material 402. Further, gaps G₁ between the strips 404a may be generally larger than gaps G₂ between the strips 404 b.Accordingly, when an etching material is placed in the vicinity of thegaps, the etching material acts upon the exposed areas and produces thesubstantially trapezoidal shape exhibited by the cross sections X and Zof the first and second blades 106 and 108.

More specifically, as best illustrated in FIG. 5, the etch resistantmaterial 404 a defines a large gap G₁ between each strip. By contrast,etch resistant strips 404 b define a smaller gap G₂ between each stripthat restricts the surface area acted upon by the etching material.Accordingly, the etching material applied on the side of the blade sheetassembly 400 adjacent strips 404 a etches away larger widths of thesheet material 402 than the etching material applied adjacent strips 404b, thereby creating an inclined etched surface which forms the lateraledges 132 of the blades 106, 108. The different sized gaps thus definethe generally trapezoidal shape and/or asymmetrical cross sectionalshape of the blades 106, 108.

Referring now to FIG. 6, an exemplary process 600 for forming a surgicalprobe 100 is described. Process 600 may begin at block 602, where firstand second blades are formed. For example, as described above, a firstblade 106 having an elongated body portion 110 and an end portion 112may be formed, e.g., in an etching process as described above. Further,a second blade may be formed including an elongated body portion 114 anda cutting edge 116 at an end of the body portion 114. Process 600 maythen proceed to block 604.

At block 604, the body portions of the first and second blades may beestablished as defining asymmetrical cross sections. For example, asdescribed above, the body portions 110 and 114 may each generally definea trapezoidal, or otherwise asymmetrical, cross sectional shape about aline B-B that is substantially parallel to the centrally disposed edges118 and 120 of the cross sections X and Z. Further, as described abovethe generally asymmetrical cross sectional shape may be created in anetching process applied to a sheet material 402. Further, this may occurduring an etching process used to form the blades, e.g., as describedabove in block 602. An etch-resistant material 404 may be secured to theopposing surfaces of the blade sheet 400 in strips 404 a, 404 b. Afterthe etch resistant material 404 is applied to the sheet material 402, anetching material may be applied to exposed areas of the sheet material402. More specifically, the etching material may generally work withingaps G₁ and G₂ on opposing sides of the sheet material 402. Furthermore,the different sized gaps G₁ and G₂ may allow exposure of differentwidths of the sheet material 402, thereby forming the asymmetricaland/or generally trapezoidal cross sectional shape of the body portions110 and 114. The cross sectional areas of each of the body portions 110and 114 may, in some exemplary illustrations, be substantially equal.

Various features of the blades 106, 108 may also be formed, such as thecutting edge 116 of the second blade 108 and the generally hooked-shapeend portion 112 of the first blade 106. The cutting edge 116 may beformed in any process that is convenient, e.g., a grinding process. Theend portion 112, including the relatively thin neck portion 122, may beformed in an etching process, or any other forming process that isconvenient. Additionally, either blade 106, 108 may be polished, e.g.,to remove any relative sharp edges where they are not desired. Process600 may then proceed to block 606.

At block 606, the first and second blades 106 and 108 may be insertedinto a tubular body 102 having a cutting aperture at a first end of thetubular body. For example, as described above the blades 106, 108 may beat least partially received within the tubular body 102, with the endportion 112 and cutting edge 116 extending outside the tubular body 102to facilitate cutting with the scissor assembly 104.

Proceeding to block 608, a first one of the blades, e.g., first blade106, may be generally fixed to the tubular body 102. For example, thefirst blade 106 may be welded to the tubular body. Additionally, thesecond blade 108 may be configured to translate longitudinally withinthe tubular body 102, e.g., to generally facilitate the relative cuttingmotion of the first and second blades 106 and 108. Process 600 may thenterminate.

Accordingly, surgical probe 100 generally allow for a tubular body 102that is reduced in size, while providing adequate strength of the blades106, 108 due to the asymmetrical and/or trapezoidal shape of the blades106, 108. Further, the exemplary process 600 generally provides a robustforming process for creating the asymmetrical and/or trapezoidal shapeof the blades 106, 108, even at the extremely small sizes typical of thesurgical probe 100.

Reference in the specification to “one example,” “an example,” “oneembodiment,” or “an embodiment” means that a particular feature,structure, or characteristic described in connection with the example isincluded in at least one example. The phrase “in one example” in variousplaces in the specification does not necessarily refer to the sameexample each time it appears.

With regard to the processes, systems, methods, heuristics, etc.described herein, it should be understood that, although the steps ofsuch processes, etc. have been described as occurring according to acertain ordered sequence, such processes could be practiced with thedescribed steps performed in an order other than the order describedherein. It further should be understood that certain steps could beperformed simultaneously, that other steps could be added, or thatcertain steps described herein could be omitted. In other words, thedescriptions of processes herein are provided for the purpose ofillustrating certain embodiments, and should in no way be construed soas to limit the claimed invention.

Accordingly, it is to be understood that the above description isintended to be illustrative and not restrictive. Many embodiments andapplications other than the examples provided would be upon reading theabove description. The scope of the invention should be determined, notwith reference to the above description, but should instead bedetermined with reference to the appended claims, along with the fullscope of equivalents to which such claims are entitled. It isanticipated and intended that future developments will occur in the artsdiscussed herein, and that the disclosed systems and methods will beincorporated into such future embodiments. In sum, it should beunderstood that the invention is capable of modification and variationand is limited only by the following claims.

All terms used in the claims are intended to be given their broadestreasonable constructions and their ordinary meanings as understood bythose skilled in the art unless an explicit indication to the contraryin made herein. In particular, use of the singular articles such as “a,”“the,” “said,” etc. should be read to recite one or more of theindicated elements unless a claim recites an explicit limitation to thecontrary.

What is claimed is:
 1. A method of forming a surgical probe, comprising: forming first and second blades, the first blade including an elongated body portion and an end portion, the second blade including an elongated body portion and a cutting edge at an end of the body portion, the cutting edge configured to cut material against the end portion of the first blade; establishing the body portions of the first and second blades as defining cross sections normal to the elongated body portions of the blades, the cross sections each defining centrally disposed edges adjacent one another, at least one of the cross sections being asymmetrical about a line substantially parallel to the centrally disposed edges; inserting the first and second blades into a tubular body having a cutting aperture at a first end of the tubular body; and fixing the first blade to the tubular body, the second blade configured to translate longitudinally within the tubular body; wherein forming the first and second blades includes: providing a sheet material having opposing surfaces; securing an etch-resistant material to the opposing surfaces; and applying an etching material to exposed areas of the sheet material.
 2. The method of claim 1, wherein forming the first and second blades includes etching the sheet material to define a pair of opposing lateral edges adjacent the centrally disposed edge, wherein a first one of the opposing faces includes the centrally disposed edges, wherein a second one of the opposing faces includes a distal edge opposite the centrally disposed edge.
 3. The method of claim 2, wherein securing the etch-resistant material to the opposing surfaces includes defining exposed gaps in the etch-resistant material, wherein the gaps on the second one of the opposing faces are larger than the gaps on the first one of the opposing faces.
 4. The method of claim 1, further comprising establishing the at least one of the cross sections as generally trapezoidal.
 5. The method of claim 1, further comprising establishing the tubular body as defining an inner diameter no greater than 0.45 millimeters (mm), and the at least one of the cross sections as having a cross-sectional area greater than 0.038 square millimeters (mm2).
 6. The method of claim 5, further comprising establishing the at least one of the cross sections as having a section modulus greater than 0.000633 millimeters-cubed (mm3).
 7. The method of claim 1, wherein the cross sections each define a substantially equal cross-sectional area. 